Tragic: Ally Calvert died as a result of natural causes after attending a party with friends Facebook

Met Commissioner Sir Bernard Hogan-Howe today apologised to the family of Bexley teenager Ally Calvert after wrongly linking his death to inhaling laughing gas.

The 18-year-old fell seriously ill after attending a party with friends in Thamesmead and died in hospital on Sunday, July 26.

Police said the death was believed to be connected with the use of nitrous oxide, or laughing gas, but a post-mortem examination found he died of natural causes.

Relatives cast doubts on the suggestion the legal high was a factor in the death, insisting an underlying heart condition was the cause.

On July 28, Sir Bernard told BBC London: “The amount of use of it makes you wonder whether combined with other things such as alcohol and other drugs it could be an awful cocktail.

"Certainly in this case it has led to a terrible outcome."

Today, Sir Bernard apologised to Mr Calvert's family having referred to his death as a "terrible outcome" during a radio debate to outlaw laughing gas.

He said: "On behalf of The Met I extended my condolences to the family and apologised for upset caused by the statements we made about Alistair's death.

On behalf of The Met I extended my condolences to the family and apologised for upset caused by the statements we made about Alistair's death

Sir Bernard Hogan-Howe

"I have apologised personally for the comments I made which inferred Alistair's tragic death was linked to the use of nitrous oxide and alcohol.

"By raising awareness of heart screening for young people I am certain Alistair's legacy will mean that good can come out of tragedy."

Jeff Boothe, the Bexley Borough Commander, added: "No inaccurate coverage should be allowed to tarnish the memory of Alistair. He deserves to be remembered for the fine, upstanding member of the community that he was."

A statement from Mr Calvert's family said: "Following the recent death of our son, grandson and brother Alistair Calvert, known as Ally to his family and friends, we would like to express our sincere gratitude for the love and support that we have received since his sudden passing.

We would like to express our sincere gratitude for the love and support that we have received since his sudden passing

The Calvert family

"As a family, we have always been aware that Alistair did not take nitrous oxide nor excessive alcohol at a party on the night that he died.

"We were also advised, following his post mortem examination, that his death was due to an undiagnosed significantly enlarged heart which caused sudden arrhythmia death syndrome. Any reference that Alistair's death was due to nitrous oxide is completely false."

Since Mr Calvert's death, a memorial fund and the #AllysBigHeart campaign has collectively raised nearly £8,000 for Cardiac Risk in the Young - a charity that supports young people with a life-threatening heart condition.